A low-energy metal-ion source for primary ion deposition and accelerated ion doping during molecular-beam epitaxy

Author(s):  
M.-A. Hasan
1989 ◽  
Vol 162 ◽  
Author(s):  
R. C. Powell ◽  
G. A. Tomasch ◽  
Y.-W. Kim ◽  
J. A. Thornton ◽  
J. E. Greene

ABSTRACTEpitaxial GaN films have been grown at temperatures between 600 and 900 °C by reactive-ion molecular-beam epitaxy. Ga was provided by evaporation from an effusion cell while nitrogen was supplied from a low-energy, single-grid, ion source. The average energy per accelerated N incident at the growing film surface was ≈ 19 eV. Films deposited on Al2O3(0112) and MgO(100)l×l substrates had wurtzite (a-GaN) and metastable zincblende (α-GaN) structures, respectively. The lattice constants were a = 0.3192 nm and c = 0.5196 nm for α;-GaN and a = 0.4531 nm for β -GaN. The room-temperature optical bandgap Eg of zincblende GaN, 3.30 eV, was found to be 0.11 eV lower than that of the hexagonal polymorph α-GaN. All films were n-type with electron carrier concentrations which decreased from 4×1018 to 8×1013 cm−3 with increasing incident N2+/Ga flux ratios between 0.63 and 3.9. Resistivities <106Ω-cm were achieved.


1987 ◽  
Vol 93 ◽  
Author(s):  
N. Hirashita ◽  
J.-P. Noel ◽  
A. Rockett ◽  
L. Markert ◽  
J.E. Greene ◽  
...  

ABSTRACTA single-grid UHV-compatible ion source was used to provide partially-ionized accelerated In+ dopant beams during Si growth by molecular beam epitaxy (MBE). Indium incorporation probabilities in 800 °C MBE Si(100). as measured by secondary ion mass spectrometry, ranged from < 10−5 (the detection limit) for thermal In to values of 0.02–0.7 for In+ acceleration energies EIn, between 50 and 400 eV. Temperature-dependent Hall-effect and resistivity measurements were carried out on Si films grown at 800 °C with EIn = 200 eV. Indium was incorporated substitutionally in electrically active sites over the entire concentration range examined. 1016— 1019 cm−3, with an acceptor level ionization energy of 165 meV. The 111 meV level associated with In-C complexes and the 18 meV “supershallow” level reported for In ion-implanted Si were not observed. Roomtemperature hole mobilities μ were higher than both annealed In-ion-implanted Si and Irvin's values for bulk Si. Phonon scattering was found to dominate at temperatures between 100 and 330 K and μ varied as T−22.


1992 ◽  
Vol 46 (12) ◽  
pp. 7551-7558 ◽  
Author(s):  
W.-X. Ni ◽  
G. V. Hansson ◽  
J.-E. Sundgren ◽  
L. Hultman ◽  
L. R. Wallenberg ◽  
...  

1982 ◽  
Vol 3 (5) ◽  
pp. 138-140 ◽  
Author(s):  
R.G. Swartz ◽  
J.H. McFee ◽  
A.M. Voshchenkov ◽  
S.N. Finegan ◽  
V.D. Archer ◽  
...  

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